Some raid bioses allow you to expand a raid-0, but not raid-1, if you where going to add more drives at regular intervals, you should use jbod.
i got 2 new ssd, waited for price to drop .and how have 2, 500,s in raid o .all is working great . but i am missing intel rapid storage ,which i want to reinstall .doing some reading and want to be assured will i need to reinstall os . to do so since i have to form a cache and also install drivers for rst.? and looking at the download from intel its in a floppy .download configuration .which i have not done before . so i can use some advise on how to properly install and download software .